The present invention relates generally to aircraft armament apparatus, and more particularly relates to ammunition magazine apparatus for aircraft-mounted machine guns.
Machine guns mounted on the exterior of an aircraft such as a helicopter, are typically supplied with ammunition by means of an elongated ammunition belt stored in a serpentined configuration within a magazine box and selectively drawn out of the box and fed to the gun. According to conventional practice, the magazine box is normally mounted inside the aircraft and the ammunition belt is routed outwardly through a suitable aircraft side wall opening to the externally mounted gun. However, the interior of the typical aircraft supplied with weaponry is often quite cramped already, and the location of ammunition magazines therein often renders it difficult to gain access to the magazines for loading and maintenance purposes.
In response to these access difficulties, another approach has been to mount the magazine within a specially designed shroud or pod which encloses the machine gun fed by the magazine. This approach is not entirely satisfactory either since an oversized, specially designed gun shroud must be used, and access to the magazine can still be somewhat tedious.
Another recently proposed solution has been to simply mount the magazine box on the outer side of the aircraft adjacent the machine gun fed by the magazine. While this approach provides for considerably easier access to the magazine box, it creates certain additional design problems which, until the present invention, have not been satisfactorily solved.
For example, there are three primary design criteria associated with an ammunition magazine box mounted externally on the side of an aircraft. First, the box must be as light as possible. Second, since the box will project outwardly from the side of the aircraft, thereby creating a source of additional drag on the aircraft during flight thereof, it should be at least relatively "smooth" from an aerodynamic standpoint. Third, the externally mounted magazine box must be highly crashworthy-i.e., be able to withstand very high accelerational or "G" loads without collapsing. Conventionally constructed magazine boxes externally mounted on the side of an aircraft have typically fallen somewhat short of meeting one or more of these primary design criteria.
Specifically, external magazine boxes of this type are usually formed from single layer metal walls, intersecured at their adjacent edges to form the overall box structure, and provided with a similarly constructed single layer metal lid. An inboard side wall of the magazine box is secured to the outer side of the aircraft to operatively mount the magazine box thereon. The single layer construction of this type of magazine box provides it with a suitably light weight but typically does not provide it with sufficient crashworthiness. To solve this problem it has heretofore been necessary to externally brace the box walls with rather sizeable outwardly projecting reinforcing ribs.
Such external bracing, while tending to alleviate the problem of high G-load collapse of the box, increases its weight to an undesirably high level while at the same time undesirably increasing the aerodynamic drag forces associated with the externally mounted magazine box.
In view of the foregoing, it can readily be seen that a need exists for an externally mountable ammunition box which is constructed to eliminate or minimize the above-mentioned and other problems, limitations and disadvantages heretofore associated with externally mounted ammunition magazine boxes of conventional construction. It is accordingly an object of the present invention to provide an externally mountable ammunition magazine box structure having a substantially improved construction.